PATH’s claim of India’s large burden of cervical cancer faulty: study

A recent study has shown that the current available data on human papillomavirus (HPV) type and cervical cancer incidence do not support the epidemiological claims made by the Programme for Appropriate Technology in Health (PATH) regarding India having a large burden of cervical cancer.

In April 2010, the Indian Council of Medical Research suspended research on the feasibility and safety of HPV vaccine in Andhra Pradesh and Gujarat amid public concerns about its safety. The study was being done for two pharmaceutical companies by PATH and was supported by the ICMR.

The paper, published in the latest edition of the Royal Society of Medicine Journal is written by I. Mattheji and P. Brhlikova of the University of Edinburg and A.M. Pollock and Queen Mary University of London, describes cervical cancer and cancer surveillance in India and reviews the epidemiological claims made by PATH.

The PATH, a U.S.-based not-for-profit non-governmental organisation undertook post-licensing observational studies on HPV vaccines in India on coverage, acceptability, feasibility and costs of the vaccines in Gujarat and Andhra Pradesh, funded by the Bill and Melinda Gates Foundation.

Cervical cancer is estimated to cause around 2,74,000 deaths a year, approximately 80 per cent of which occur in the developing world. Guidelines for cervical cancer screening are implemented in few States in India. HPV is associated with cervical cancer and of the 100 HPV types, 18 have been categorised as high risk types or possible high risk types for cervical cancer. HPV types 16 and 18 are said to account for approximately 70 per cent of all cervical cases in India.

According to the latest study, there is no general account in the literature of cancer surveillance in India. The two main agencies involved in reporting incidence, prevalence and mortality of cervical cancer in India are the National Cancer Registry Programme (NCRP) and the International Agency for Research on Cancer (IARC).

The latest study says that PATH does not cite any of the cancer data on Andhra Pradesh or Gujarat. There is no NCRP or other cancer registry in Andhra Pradesh, and neither C15 (Cancer Incidence in five continents) nor GLOBOCAN (global database across the world) published data for this State. Age-adjusted incidence rates are 10.16 in Hyderabad and 14.29 per 1 lakh in Nellore (2001-02).

There are two cancer registries in Gujarat, one urban and the other rural, which cover only Ahmedabad districts. The rural registry shows an age-adjusted incidence rate of 8.5 per 1 lakh (2006-08); the urban registry shows this rate as 9.1 per 1 lakh (2004-05). The coverage is 18.9 million people. Gujarat has low incidence rates and few data on mortality rates are available.

The study was to investigate whether to implement an HPV vaccination programme with PATH claiming that “in raw numbers, India has the largest burden of cancer of cervix of any country worldwide.” The new study says this claim is not supported by the references, moreover data from the cancer registries in Gujarat has not been cited. The two States were selected “based on cervical cancer burden and uptake of other vaccines being in the middle range for certain variables (eg. immunisation coverage).” There is no reference provided for this.

Contrary to PATH’s claim, the overall incidence and mortality rate of cervical cancer is low in India. Age-adjusted cervical cancer incidence rates of India are also low compared to estimates of 50 per 1,00,000 in Zimbabwe and 38.2 in Brazil.

However, the World Health Organisation advises that the epidemiology of the disease should be known and be of sufficient importance to justify its prioritisation, and that surveillance systems should be capable of assessing the impact of vaccine intervention following its introduction. “This study shows an absence of epidemiological data in support of HPV vaccine studies by PATH in the two States, let alone any roll out across the rest of India. Recent studies of HPV show an apparent decrease in cervical cancer incidence, which must also be taken into account,” says the study ‘Do cervical cancer data justify HPV vaccination in India? Epidemiological data sources and comprehensiveness’.

Of the five studies that PATH cites in relation to cervical cancer or HPV epidemiology, one study could not be traced; the home-based cancer registry report is not comprehensive and does not provide age-adjusted cervical cancer incidence rates and the three remaining studies did not examine epidemiology of cancer but reported HPV prevalence and type distribution. Only one study was conducted in A.P. and none in Gujarat. The three studies were conducted in rural populations in the south and urban populations in the south and north of India.

Cervical cancer surveillance in Gujarat and Andhra Pradesh is incomplete and the data that are available were not used or cited by PATH, the new study says.